Laws of motion

4. The rate at which a body moves; a scalar quantity.
6. Any object, generally in studies of motion.
7. A mathematical quantity that describes a magnitude and direction.
8. Complete path travelled by an object; a scalar quantity.
10. goal of a thought experiment is to explore potential consequences of the principle in question without performing the experiment.
13. The law that states that all objects continue with constant motion unless acted on by an unbalanced force.
14. The vector sum of all the forces that act upon an object.
15. The speed of a body, including its direction, velocity is a vector quantity.
16. A simple device involving a solid arm and a fulcrum, which can move to multiply a force applied to one part.
18. A contact force that is perpendicular to the surface that an object makes contact with.
19. Devices that increase the speed of, or distance travelled by, an object.

1. A diagram of an object and its surroundings with arrows indicating all the forces acting on it.
2. The rate of change of a body’s velocity, including its direction; acceleration is a vector quantity – a body can accelerate by moving faster or slower, or by changing direction.
3. The shortest distance from the initial position to the final position with a direction given; a vector quantity.
5. The law that states ‘for every action force there is an equal and opposite reaction force’; if A pushes on B, then B pushes back on A.
9. The law described by the equation; F = ma.
11. The degree of reproducibility or agreement between repeated measurements.
12. The property of a body affected by a gravitational field; also the inertia of a body.
17. How close the measured value is to the true value.